import random
def main():
    list_num = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
    list_str = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
    veri_str = random.sample(list_str, 2)
    veri_num = random.sample(list_num, 2)
    veri_out = random.sample(veri_num + veri_str, 4)
    veri_res = str(veri_out[0]) + str(veri_out[1]) + str(veri_out[2]) + str(veri_out[3])
    print(veri_res)
if __name__ == '__main__':
    main()

